The present invention relates to a brake installation with master cylinder and brake booster but no push rod and notably a brake installation with master cylinder associated with a brake booster comprising an actuator piston controlled by the motor of the brake booster and acting on the primary piston of the master cylinder by means of a reaction disk against which the primary piston rests and also, if necessary, for a safety operation, the hydraulic actuator connected to the control rod actuated by the brake pedal.
Brake systems with master cylinder and brake booster use, at the connection between the actuator piston of the brake booster and the piston (primary piston) of the master cylinder, a connection via a push rod pressed against the reaction disk, on the side of the master cylinder. This push rod is a part of complex shape consisting of two portions: a mushroom-shaped rear portion, the flat head of which is pressed against the whole front face, on the side of the master cylinder, of the reaction disk and which supports a second part, inserted into the rod of the first in order to press against the bottom of the primary piston.
When the master cylinder and the brake booster are assembled, the free travel between the reaction disk of the actuator and the primary piston is first measured and the length of the push rod is adapted by compressing it as a function of what is necessary to limit the free travel.
This action, relatively complicated and costly to apply, is necessary because of the manufacturing and installation tolerances which exist at the actuator piston.